Enrobing apparatus

ABSTRACT

Apparatus for the automatic distribution of a powdered product at the interior of the treatment trough or drum of an apparatus for enrobing various articles such as food or pharmaceutical products, comprising distribution means extending along the entire length of the trough and consisting of a tube which is at least partially perforated and at the interior of which there is disposed a powder feeding screw the helicoidal thread of which carries on its periphery a brush adapted to pass the powder through the perforations of this tube, a shutter for partial closure being provided at the perforated portion of the tube to control the extent of distribution of the powder.

United States Patent 11 1 1111 3,890,923 Dumoulin June 24, 1975 [54'] ENROBING APPARATUS 2,883,274 4/1959 Ceresna 264/117 X 3,404,659 10/1968 Croston 118/24 [761 Inventor Bernard. Dumulm, 58 avenue (16 3,724,416 4/1973 Diamond ct a]. 118/7 Bonneull, 94 La Varenne I France Primary Examiner-John P. Mclntosh 22 Filed; Jam 3 1974 Attorney, Agent, or Firm-Michael S. Striker [21.] App]. NO.Z 430,400 57 ABSTRACT 2 Apparatus for the automatic distribution of a pow- [30] Foreign Application Priority Data dered product at the interior of the treatment trough Jan. 4, 1973 France 73.00218 or drum Of an apparatus for ehrehing various articles such as food or pharmaceutical products, comprising 52 us. c1. 118/19; 118/24; 118/303 distribution means extending along the entire length of 51 Int. Cl A23g 3/20 the trough and censistihg of a tube which is at least [58] Field of Search 118/19, 303, 312, 308, Partially Perforated and at the interior of which there 4; 259 4; 2 4 17 is disposed a powder feeding screw the helicoidal thread of which carries on its periphery a brush [56] References Cited adapted to pass the powder through the perforations of this tube, a shutter for partial closure being pro- 003 441 Z PATENTS 18/312 X Vided at the perforated portion of the tube to control a on 1.713.568 5/1929 Swenson 259/3 the extent of dlsmbuno" the powder 1.819557 8/1931 Hunter 118/19 3 Claims, 3 Drawing Figures PATENTEDJUN 24 I915 SHEET ENROBING APPARATUS The present invention relates to apparatus used for the enrobing or conversion into dragee form of various articles such as food products or pharmaceutical products.

These apparatus generally consist of a rotary trough or drum at the interior of which the liquid enrobing solution is poured onto the products to be treated. These are thus enrobed with a layer of this solution which solidifies during the rotation of the drum. The enrobing solution. for example a sugar syrup, is poured onto the products to be treated by means of projection pipes which form diffusers and which are disposed at the interior of the drum along its entire length.

There is obtained in this manner a uniform enrobing of the products to be treated. However, in the case of dragees there is obtained in many cases an enlargement of the dragees by powdering them with powdered sugar or starch after enrobing them by means of a solution of liquid sugar. Furthermore, the process of conversion into dragees, known under the French term tendre, is carried out in a similar manner, only the composition of the syrup being different. In effect, in such a case, there is a syrup constituted by sugar and glucose.

At the present time, in cases of this type the powdering of the products in the course of conversion into dragees is carried out manually, which presents a certain number of difficulties. Moreover, the distribution of the projected powder is often irregular, which lowers the quality of the products obtained.

Accordingly the present invention has for its object an apparatus for carrying out the automatic distribu tion of a powdered additive product in the interior of the trough of an enrobing apparatus such as described above.

This apparatus comprises a powder distribution means extending along the entire length of the trough and consisting of a tube which is at least partly perforated, at the interior of which there is disposed a rotary powder feeding screw, the helicoidal thread of which carries on its circumference a brush adapted to move the powder across the perforations of this tube. Furthermore, a partial closing shutter is provided opposite the perforated portion of the latter to control the rate of distribution of the powder.

In an advantageous form of construction, the present apparatus is arranged in such a manner as to provide re-cycling ofa part of the powder circulating in the distribution tube at the end of the latter. This permits the obtaining of a very great regularity of distribution, irrespective of the rate of distribution.

The present invention likewise has for its object enrobing apparatus provided with such a distribution device. However, other features and advantages thereof will appear in the course of the following description, given with reference to the accompanying drawing by way of example, and on which FIG. 1 is a schematic view in axial section of the present powder distribution device provided in an enrobing machine;

FIG. 2 is a schematic view in transverse section;

FIG. 3 is a partial view in axial section of the feeding screw provided in the powder distribution tube.

The apparatus shown equips the rotary drum of a known enrobing apparatus which is intended to carry out the enrobing or conversion into dragees of articles such as food or pharmaceutical products. For this purpose. this drum includes pipes for carrying out projection of the enrobing liquid onto the products to be treated. However, these pipes are not shown on the drawings because they do not form part of the present invention and they can be of various types already known or not.

The apparatus according to the invention comprises distribution means constituted by a tube 2 which extends along the entire length of the drum 1, parallel to the axis of the latter. This tube is fixed and it extends to the extremities of this drum which can rotate about it, this drum being driven by any appropriate means, not shown on the drawings, because it obviously does not form any part of the invention.

On at least part of its surface, the wall of the tube 2 is cut away and comprises at this place a fitting 3 of grille material or perforated sheet metal adapted to allow passage of the powder to be distributed. Opposite this perforated or apertured zone, there is provided a movable shutter 4 for partial closing. This takes the form of an incurved strip following the shape of this tube 2 and which is mounted in such a manner as to be able to be turned about it. It is thus possible to modify the angular position of this shutter in such a manner as to free a larger or smaller surface of the perforated portion 3 of the distribution tube, which permits definitively the controlling of the rate of projection of the powder distributed by this tube.

This latter encloses an Archimedean screw, denoted by the general reference 5 which is driven in rotation by a motor 5a. This screw, which is intended to carry out the driving of the powder in the direction of the arrow F, is constituted by a rotary shaft 6 about which there is provided a metallic strip 7 of helicoidal shape, forming the thread of this screw. This strip can be fixed on this shaft, for example by a welded seam.

This strip carries on its circumference a brush 8 bearing against the internal wall of the distribution ramp and which thus avoids any risk of warping of the wall of the perforated part thereof. Moreover, during its rotation, this brush forces the powder to pass across the perforations of the distribution ramp. In the example of construction shown, the tufts of hair of this brush are fixed in a profiled element 9 in the form of'a gutter placed against one of the faces of the helicoidal strip 7. However, this brush could be constructed in any other appropriate manner.

The upstream end 2a of the distribution ramp is closed at the end and it is fed with powder to be projected by means of a funnel l0 constituting a sort of tamping element. In effect this funnel is itself fed by a funnel of larger dimensions to which it is coupled by a channel 11. Meanwhile, the opening of this principal funnel is controlled by a system in which automatic control of the level of the buffer funnel 10. This system can comprise a detecting probe 12 shown schematically on FIG. 2. Preferably, intermediate funnel 10 likewise comprises an electromagnetic vibrator of variable frequency to facilitate the flow of the powder and avoiding all risks of formation of cavities at the interior of this funnel.

The downstream end of the distribution tube 2 is coupled to a conduit 13 ensuring its coupling with a recycling conduit 14 opening into the intermediate funnel 10. This conduit is inclined and the flow of the powder coming from the distribution ramp takes place by gravity. The conduit 14 encloses an Archimedean screw 15 intended to ensure the driving of this portion of'the powder as far as the intermediate funnel 10.

This possibility of recycling is extremely advantageous.

In effect it permits the provision of an output of circulation of the powder at the interior of the tube 2 which is greater than the maximum possible distribution output through the perforated part of this tube. Under these conditions, there is always an excess of non-distributed powder at the downstream extremity of this ramp which can be recycled by means of the conduit 14. This accordingly ensures a regular spreading of the distribution of the powder along the entire length of the ramp, even when this latter has a length of 2.50

meters or more.

Meanwhile, another essential advantage of the present device resides in the perfect operation thereof to bring about the distribution of the powder at the interior of the treatment trough 1. This is due to the fact that the Archimedean screw 5 has not only the function of driving the powder but also to compel it to pass through the perforations of the perforated portion of the ramp, this being by means of the helicoidal brush 8. Furthermore, in the absence of this brush, the yield obtained would be less satisfactory. In regard to this, it should be noted that this brush likewise has the advantage of avoiding any risk of warping of the perforations of the distribution ramp.

It is possible to vary the output of powder by varying the speed of the motor-reducer employed for driving the screw 5 provided in this ramp.

The present device can be installed in enrobing or dragee apparatus of various kinds. it can be employed to bring about an accelerated enlargement of the dragees by powdering them with sugar or with starch or with a mixture of sugar and starch, after completion of the enrobing stage by means of a liquid syrup. However, this apparatus can likewise by used to carry out so-called tendre" dragee manufacture accompanied by powdering with sugar or any other appropriate powdered material, the enrobing layer being obtained in such a case by means of a syrup of sugar and glucose.

As has already been indicated, the invention also has for its object enrobing apparatus provided with such a device. These can 'be employed for uses of very varied nature each time that it is desired to carry out enrobing of various articles, for example food or pharmaceutical products, and likewise providing powdering with a powdered product.

I claim:

1. Apparatus for coating various articles, such as food or pharmaceutical articles, with a powdered product, comprising an elongated hollow treatment drum having opposite ends, said drum being rotatable about a horizontal axis and adapted to receive said articles; distributing means extending through the entire length of said drum and comprising a tube having a first end adapted to receive said powdered product and an opposite end, said tube being provided in a portion thereof extending within the drum from the region of one of said opposite ends of the drum to the region of the other of said opposite ends with perforations, a rotating feed screw extending substantially coaxially through said tube, a helicoidal brush provided on the periphery of said feed screw for passing the powdered product through said perforations, and an adjustable shutter extending along said portion of said tube for partial closure of said perforations; a recycling conduit communicating with said first and said opposite end of said tube; and means for feeding the powdered product through said recycling conduit.

2. Apparatus as defined in claim 1, and further comprising a main feeding funnel containing said powdered product; an intermediate funnel at which said recycling conduit terminates, said intermediate funnel communicating with said first end of said tube; an outlet provided on said main funnel and communicating with said intermediate funnel; and a control system controlling said outlet, said system including sensing means for sensing the level of the powdered product in said intermediate funnel.

3. Apparatus as defined in claim 1, wherein said means for feeding the powdered product through said recycling conduit comprises an additional feed screw. l 

1. Apparatus for coating various articles, such as food or pharmaceutical articles, with a powdered product, comprising an elongated hollow treatment drum having opposite ends, said drum being rotatable about a horizontal axis and adapted to receive said articles; distributing means extending through the entire length of said drum and comprising a tube having a first end adapted to receive said powdered product and an opposite end, said tube being provided in a portion thereof extending within the drum from the region of one of said opposite ends of the drum to the region of the other of said opposite ends with perforations, a rotating feed screw extending substantially coaxially through said tube, a helicoidal brush provided on the periphery of said feed screw for passing the powdered product through said perforations, and an adjustable shutter extending along said portion of said tube for partial closure of said perforations; a recycling conduit communicating with said first and said opposite end of said tube; and means for feeding the powdered product through said recycling conduit.
 2. Apparatus as defined in claim 1, and further comprising a main feeding funnel containing said powdered product; an intermediate funnel at which said recycling conduit terminates, said intermediate funnel communIcating with said first end of said tube; an outlet provided on said main funnel and communicating with said intermediate funnel; and a control system controlling said outlet, said system including sensing means for sensing the level of the powdered product in said intermediate funnel.
 3. Apparatus as defined in claim 1, wherein said means for feeding the powdered product through said recycling conduit comprises an additional feed screw. 